From 6330f22bf4bd9e4e39315dc41bdb63c4de654c56 Mon Sep 17 00:00:00 2001
From: Daniel Young Lee <danielylee@google.com>
Date: Thu, 7 Dec 2023 09:28:44 +0900
Subject: [PATCH 1/2] Memoize firestore.getDatabase.

---
 src/deploy/functions/services/firestore.ts | 20 +++++++++++++++++++-
 src/gcp/firestore.ts                       |  2 +-
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/src/deploy/functions/services/firestore.ts b/src/deploy/functions/services/firestore.ts
index d4eb39b45d5..dade0774b8e 100644
--- a/src/deploy/functions/services/firestore.ts
+++ b/src/deploy/functions/services/firestore.ts
@@ -2,6 +2,24 @@ import * as backend from "../backend";
 import * as firestore from "../../../gcp/firestore";
 import { FirebaseError } from "../../../error";
 
+const dbCache = new Map<string, firestore.Database>();
+
+/**
+ * A memoized version of firestore.getDatabase that avoids repeated calls to the API.
+ *
+ * @param project the project ID
+ * @param databaseId the database ID or "(default)"
+ */
+async function getDatabase(project: string, databaseId: string): Promise<firestore.Database> {
+  const key = `${project}/${databaseId}`;
+  if (dbCache.has(key)) {
+    return dbCache.get(key)!;
+  }
+  const db = await firestore.getDatabase(project, databaseId);
+  dbCache.set(key, db);
+  return db;
+}
+
 /**
  * Sets a firestore event trigger's region to the firestore database region.
  * @param endpoint the firestore endpoint
@@ -9,7 +27,7 @@ import { FirebaseError } from "../../../error";
 export async function ensureFirestoreTriggerRegion(
   endpoint: backend.Endpoint & backend.EventTriggered
 ): Promise<void> {
-  const db = await firestore.getDatabase(
+  const db = await getDatabase(
     endpoint.project,
     endpoint.eventTrigger.eventFilters?.database || "(default)"
   );
diff --git a/src/gcp/firestore.ts b/src/gcp/firestore.ts
index e5897c75f66..c870fa95485 100644
--- a/src/gcp/firestore.ts
+++ b/src/gcp/firestore.ts
@@ -8,7 +8,7 @@ const apiClient = new Client({
   urlPrefix: firestoreOrigin,
 });
 
-interface Database {
+export interface Database {
   name: string;
   uid: string;
   createTime: string;

From 762c4e3ae47fdb790242f2aee4affd1cb437c0b8 Mon Sep 17 00:00:00 2001
From: Daniel Young Lee <danielylee@google.com>
Date: Thu, 7 Dec 2023 09:33:35 +0900
Subject: [PATCH 2/2] Add changelog.

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e69de29bb2d..c60322ef68a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -0,0 +1 @@
+- Fix bug where deploying Firestore function resulted in redudant API calls to the Firestore API (#6583).